Mrs Fordyce, who sat on Dundee City Council for 13 years and was chair of the Dundee East constituency branch, said ministers are “breaking the laws of God and man”.

The Roman Catholic also doubted Government assurances to protect freedom of speech and religion claiming churches who refuse to conduct the ceremonies would still face challenges in European courts.

There was a consultation on this issue. Over 70,000 people responded and the majority opposed gay marriage. How is this democracy? I still believe in independence and I would love to see my country become a free nation again as it was 300 years ago

Liz Fordyce

Mr Salmond and his ministers sparked anger last month when they confirmed that they would bring forward a Bill on the contentious issue despite thousands of objections.

Mrs Fordyce said: “There was a consultation on this issue. Over 70,000 people responded and the majority opposed gay marriage. How is this democracy? I still believe in independence and I would love to see my country become a free nation again as it was 300 years ago.

“But I have grave misgivings that it will become a dictatorship and the party’s attitude to this issue has shown they are willing to ignore the people and act like dictators.”

The SNP is adamant that no church or religious celebrant would be compelled to marry couples of the same sex.

But Mrs Fordyce, who stepped down from Dundee City Council at May’s elections, added: “Gay marriage is not just breaking the laws of God, it is breaking the laws of man.

“It’s ludicrous if anyone seriously thinks priests, rabbis, ministers and other religious leaders will be able to say no to this.

“They might tell people they can’t get married in their church, but what happens when European law kicks in? Leaders of all denominations are being left very vulnerable to persecution here.”

An SNP spokesman said: “Liz Fordyce has strong views on the issue and we respect her decision.”